Turbine blades are the primary elements of wind turbines for converting wind energy into electrical energy. The blades have the cross-sectional profile of an airfoil such that, during operation, air flows over the blade producing a pressure difference between the sides. Consequently, a lift force, which is directed from a pressure side towards a suction side, acts on the blade. The lift force generates torque on the main rotor shaft, which is geared to a generator for producing electricity.
The turbine blades typically consist of an upper (suction side) shell and a lower (pressure side) shell that are bonded together at bond lines along the trailing and leading edges of the blade. The bond lines are generally formed by applying a suitable bonding paste or compound along the bond line with a minimum design bond width between the shell members. These bonding lines, particularly at the trailing edge of the blade, are a critical design constraint of the blades. A significant number of turbine blade field failures are bond line related, with trailing edge failures being the most common. Separation of the bond line along the trailing edge of an operational turbine blade can result in a catastrophic failure and damage to the wind turbine. In this regard, ensuring that the minimum design bond width of the bonding paste is achieved, particularly along the trailing edge bond line, is important.
Accordingly, the industry would benefit from an improved method and system for verifying that the minimum bond width of bond paste has been applied between the turbine blade shell members, particularly along the trailing edge of the blade.